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Bekker RA, Obertopp N, Redler G, Penagaricano J, Caudell JJ, Yamoah K, Pilon-Thomas S, Moros EG, Enderling H. Spatially fractionated GRID radiation potentiates immune-mediated tumor control. Radiat Oncol 2024; 19:121. [PMID: 39272128 PMCID: PMC11401399 DOI: 10.1186/s13014-024-02514-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Accepted: 08/26/2024] [Indexed: 09/15/2024] Open
Abstract
BACKGROUND Tumor-immune interactions shape a developing tumor and its tumor immune microenvironment (TIME) resulting in either well-infiltrated, immunologically inflamed tumor beds, or immune deserts with low levels of infiltration. The pre-treatment immune make-up of the TIME is associated with treatment outcome; immunologically inflamed tumors generally exhibit better responses to radio- and immunotherapy than non-inflamed tumors. However, radiotherapy is known to induce opposing immunological consequences, resulting in both immunostimulatory and inhibitory responses. In fact, it is thought that the radiation-induced tumoricidal immune response is curtailed by subsequent applications of radiation. It is thus conceivable that spatially fractionated radiotherapy (SFRT), administered through GRID blocks (SFRT-GRID) or lattice radiotherapy to create areas of low or high dose exposure, may create protective reservoirs of the tumor immune microenvironment, thereby preserving anti-tumor immune responses that are pivotal for radiation success. METHODS We have developed an agent-based model (ABM) of tumor-immune interactions to investigate the immunological consequences and clinical outcomes after 2 Gy × 35 whole tumor radiation therapy (WTRT) and SFRT-GRID. The ABM is conceptually calibrated such that untreated tumors escape immune surveillance and grow to clinical detection. Individual ABM simulations are initialized from four distinct multiplex immunohistochemistry (mIHC) slides, and immune related parameter rates are generated using Latin Hypercube Sampling. RESULTS In silico simulations suggest that radiation-induced cancer cell death alone is insufficient to clear a tumor with WTRT. However, explicit consideration of radiation-induced anti-tumor immunity synergizes with radiation cytotoxicity to eradicate tumors. Similarly, SFRT-GRID is successful with radiation-induced anti-tumor immunity, and, for some pre-treatment TIME compositions and modeling parameters, SFRT-GRID might be superior to WTRT in providing tumor control. CONCLUSION This study demonstrates the pivotal role of the radiation-induced anti-tumor immunity. Prolonged fractionated treatment schedules may counteract early immune recruitment, which may be protected by SFRT-facilitated immune reservoirs. Different biological responses and treatment outcomes are observed based on pre-treatment TIME composition and model parameters. A rigorous analysis and model calibration for different tumor types and immune infiltration states is required before any conclusions can be drawn for clinical translation.
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Affiliation(s)
- Rebecca A Bekker
- Department of Integrated Mathematical Oncology, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL, 33612, USA
- Cancer Biology Ph.D. Program, University of South Florida, Tampa, FL, 33612, USA
| | - Nina Obertopp
- Department of Immunology, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL, 33612, USA
- Cancer Biology Ph.D. Program, University of South Florida, Tampa, FL, 33612, USA
| | - Gage Redler
- Department of Radiation Oncology, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL, 33612, USA
| | - José Penagaricano
- Department of Radiation Oncology, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL, 33612, USA
| | - Jimmy J Caudell
- Department of Radiation Oncology, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL, 33612, USA
| | - Kosj Yamoah
- Department of Radiation Oncology, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL, 33612, USA
| | - Shari Pilon-Thomas
- Department of Immunology, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL, 33612, USA
| | - Eduardo G Moros
- Department of Radiation Oncology, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL, 33612, USA
| | - Heiko Enderling
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA.
- Institute for Data Science in Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA.
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Ginn J, Duriseti S, Mazur T, Spraker M, Kavanaugh J. A Dose Accumulation Assessment of Alignment Errors During Spatially Fractionated Radiation Therapy. Pract Radiat Oncol 2024; 14:e283-e290. [PMID: 38081359 DOI: 10.1016/j.prro.2023.11.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 11/29/2023] [Accepted: 11/30/2023] [Indexed: 01/27/2024]
Abstract
PURPOSE Spatially fractionated radiation therapy (SFRT) techniques produce high-dose peaks and low-dose valleys within a tumor. Lattice stereotactic body radiation therapy (SBRT) is a form a SFRT delivered across 5 fractions. Because of the high spatial dose gradients associated with SFRT, it is critical for fractionated SFRT patients to be aligned correctly for treatment. Here we investigate the dosimetric effect of daily alignment uncertainty through a dose accumulation study. METHODS AND MATERIALS Dose accumulation was retrospectively performed for 10 patients enrolled on a phase 1 trial. Lattice stereotactic body radiation therapy was completed in 5 fractions with 20 Gy prescribed to the entire tumor and a simultaneous integrated boost of 66.7 Gy prescribed to a set of regularly spaced high-dose spheres. Daily alignment error was quantified through manually selected landmarks in both the planning computed tomography scan and daily cone beam computed tomography. The dosimetric effect of alignment errors was quantified by translating the isocenter in the treatment planning system by the daily average alignment error. Large errors were simulated by translating isocenter 5 and 10 mm for 1 and 2 fractions, independently assessing errors in the superior-inferior and axial directions. The reduction of dose gradients was quantified using the dose ratio (DR) of the mean dose in the high-dose and low-dose spheres. RESULTS The average alignment error was 1.8 mm across the patient population resulting in minor smoothing of the high- and low-dose distributions in the dose accumulation. Quantitatively, the DR decreased from 3.42 to 3.32 (P = .093) in the dose accumulation study. The simulated worst case was an inferior-superior shift of 10 mm for 2 fractions where the average DR decreased to 2.72 (P = .0001). CONCLUSIONS The dose accumulation study revealed on average DR only decreased from 3.42 to 3.32. However, setup errors >5 mm resulted in larger dosimetric degradation, reflecting a larger effect for individual high-dose spheres within regions exhibiting larger displacements.
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Affiliation(s)
- John Ginn
- Department of Radiation Oncology, Duke University, Durham, North Carolina
| | - Sai Duriseti
- Department of Radiation Oncology, University of California Los Angeles, Los Angeles, California
| | - Thomas Mazur
- Department of Radiation Oncology, Washington University in St Louis, St. Louis, Missouri
| | | | - James Kavanaugh
- Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota.
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Ahmed MM, Wu X, Mohiuddin M, Perez NC, Zhang H, Amendola BE, Malachowska B, Mohiuddin M, Guha C. Optimizing GRID and Lattice Spatially Fractionated Radiation Therapy: Innovative Strategies for Radioresistant and Bulky Tumor Management. Semin Radiat Oncol 2024; 34:310-322. [PMID: 38880540 DOI: 10.1016/j.semradonc.2024.05.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/18/2024]
Abstract
Treating radioresistant and bulky tumors is challenging due to their inherent resistance to standard therapies and their large size. GRID and lattice spatially fractionated radiation therapy (simply referred to GRID RT and LRT) offer promising techniques to tackle these issues. Both approaches deliver radiation in a grid-like or lattice pattern, creating high-dose peaks surrounded by low-dose valleys. This pattern enables the destruction of significant portions of the tumor while sparing healthy tissue. GRID RT uses a 2-dimensional pattern of high-dose peaks (15-20 Gy), while LRT delivers a three-dimensional array of high-dose vertices (10-20 Gy) spaced 2-5 cm apart. These techniques are beneficial for treating a variety of cancers, including soft tissue sarcomas, osteosarcomas, renal cell carcinoma, melanoma, gastrointestinal stromal tumors (GISTs), pancreatic cancer, glioblastoma, and hepatocellular carcinoma. The specific grid and lattice patterns must be carefully tailored for each cancer type to maximize the peak-to-valley dose ratio while protecting critical organs and minimizing collateral damage. For gynecologic cancers, the treatment plan should align with the international consensus guidelines, incorporating concurrent chemotherapy for optimal outcomes. Despite the challenges of precise dosimetry and patient selection, GRID RT and LRT can be cost-effective using existing radiation equipment, including particle therapy systems, to deliver targeted high-dose radiation peaks. This phased approach of partial high-dose induction radiation therapy with standard fractionated radiation therapy maximizes immune modulation and tumor control while reducing toxicity. Comprehensive treatment plans using these advanced techniques offer a valuable framework for radiation oncologists, ensuring safe and effective delivery of therapy for radioresistant and bulky tumors. Further clinical trials data and standardized guidelines will refine these strategies, helping expand access to innovative cancer treatments.
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Affiliation(s)
- Mansoor M Ahmed
- Department of Radiation Oncology, Albert Einstein College of Medicine, Bronx, NY.
| | - Xiaodong Wu
- Executive Medical Physics Associates, Miami, FL
| | - Majid Mohiuddin
- Radiation Oncology Consultants and Northwestern Proton Center, Warrenville, IL
| | | | - Hualin Zhang
- Department of Radiation Oncology, University of Southern California, Los Angeles, CA
| | | | - Beata Malachowska
- Department of Radiation Oncology, Albert Einstein College of Medicine, Bronx, NY
| | | | - Chandan Guha
- Department of Radiation Oncology, Montefiore Medical Center, Bronx, NY
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Li H, Mayr NA, Griffin RJ, Zhang H, Pokhrel D, Grams M, Penagaricano J, Chang S, Spraker MB, Kavanaugh J, Lin L, Sheikh K, Mossahebi S, Simone CB, Roberge D, Snider JW, Sabouri P, Molineu A, Xiao Y, Benedict SH. Overview and Recommendations for Prospective Multi-institutional Spatially Fractionated Radiation Therapy Clinical Trials. Int J Radiat Oncol Biol Phys 2024; 119:737-749. [PMID: 38110104 PMCID: PMC11162930 DOI: 10.1016/j.ijrobp.2023.12.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 10/30/2023] [Accepted: 12/09/2023] [Indexed: 12/20/2023]
Abstract
PURPOSE The highly heterogeneous dose delivery of spatially fractionated radiation therapy (SFRT) is a profound departure from standard radiation planning and reporting approaches. Early SFRT studies have shown excellent clinical outcomes. However, prospective multi-institutional clinical trials of SFRT are still lacking. This NRG Oncology/American Association of Physicists in Medicine working group consensus aimed to develop recommendations on dosimetric planning, delivery, and SFRT dose reporting to address this current obstacle toward the design of SFRT clinical trials. METHODS AND MATERIALS Working groups consisting of radiation oncologists, radiobiologists, and medical physicists with expertise in SFRT were formed in NRG Oncology and the American Association of Physicists in Medicine to investigate the needs and barriers in SFRT clinical trials. RESULTS Upon reviewing the SFRT technologies and methods, this group identified challenges in several areas, including the availability of SFRT, the lack of treatment planning system support for SFRT, the lack of guidance in the physics and dosimetry of SFRT, the approximated radiobiological modeling of SFRT, and the prescription and combination of SFRT with conventional radiation therapy. CONCLUSIONS Recognizing these challenges, the group further recommended several areas of improvement for the application of SFRT in cancer treatment, including the creation of clinical practice guidance documents, the improvement of treatment planning system support, the generation of treatment planning and dosimetric index reporting templates, and the development of better radiobiological models through preclinical studies and through conducting multi-institution clinical trials.
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Affiliation(s)
- Heng Li
- Department of Radiation Oncology, John Hopkins University, Baltimore, Maryland.
| | - Nina A Mayr
- College of Human Medicine, Michigan State University, East Lansing, Michigan
| | - Robert J Griffin
- Department of Radiation Oncology, University of Arkansas for Medical Science, Little Rock, Arkansas
| | - Hualin Zhang
- Department of Radiation Oncology, University of Southern California, Los Angeles, California
| | - Damodar Pokhrel
- Department of Radiation Medicine, University of Kentucky, Lexington, Kentucky
| | - Michael Grams
- Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota
| | - Jose Penagaricano
- Department of Radiation Oncology, Moffitt Cancer Center, Tampa, Florida
| | - Sha Chang
- Department of Radiation Oncology, University of North Carolina, Chapel Hill, North Carolina
| | | | - James Kavanaugh
- Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota
| | - Liyong Lin
- Department of Radiation Oncology, Emory University, Atlanta, Georgia
| | - Khadija Sheikh
- Department of Radiation Oncology, John Hopkins University, Baltimore, Maryland
| | - Sina Mossahebi
- Department of Radiation Oncology, University of Maryland, Baltimore, Maryland
| | - Charles B Simone
- Department of Radiation Oncology, New York Proton Center, New York, New York
| | - David Roberge
- Department of Radiation Oncology, Centre Hospitalier de l'Université de Montréal (CHUM), Montréal, Québec, Canada
| | - James W Snider
- South Florida Proton Therapy Institute, 5280 Linton Blvd, Delray Beach, Florida
| | - Pouya Sabouri
- Department of Radiation Oncology, University of Arkansas for Medical Science, Little Rock, Arkansas
| | - Andrea Molineu
- Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Ying Xiao
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Stanley H Benedict
- Department of Radiation Oncology, University of California, Davis, Sacramento, California
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Zhang H, Wu X. Which Modality of SFRT Should be Considered First for Bulky Tumor Radiation Therapy, GRID or LATTICE? Semin Radiat Oncol 2024; 34:302-309. [PMID: 38880539 DOI: 10.1016/j.semradonc.2024.04.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/18/2024]
Abstract
Spatially fractionated radiation therapy (SFRT), also known as the GRID and LATTICE radiotherapy (GRT, LRT), the concept of treating tumors by delivering a spatially modulated dose with highly non-uniform dose distributions, is a treatment modality of growing interest in radiation oncology, physics, and radiation biology. Clinical experience in SFRT has suggested that GRID and LATTICE therapy can achieve a high response and low toxicity in the treatment of refractory and bulky tumors. Limited initially to GRID therapy using block collimators, advanced, and versatile multi-leaf collimators, volumetric modulated arc technologies and particle therapy have since increased the capabilities and individualization of SFRT and expanded the clinical investigation of SFRT to various dosing regimens, multiple malignancies, tumor types and sites. As a 3D modulation approach outgrown from traditional 2D GRID, LATTICE therapy aims to reconfigure the traditional SFRT as spatial modulation of the radiation is confined solely to the tumor volume. The distinctively different beam geometries used in LATTICE therapy have led to appreciable variations in dose-volume distributions, compared to GRID therapy. The clinical relevance of the variations in dose-volume distribution between LATTICE and traditional GRID therapies is a crucial factor in determining their adoption in clinical practice. In this Point-Counterpoint contribution, the authors debate the pros and cons of GRID and LATTICE therapy. Both modalities have been used in clinics and their applicability and optimal use have been discussed in this article.
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Affiliation(s)
- Hualin Zhang
- Executive Medical Physics Associates, Miami, FL..
| | - Xiaodong Wu
- Department of Radiation Oncology, University of Southern California, Los Angeles, CA
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Jenkins SV, Johnsrud AJ, Dings RPM, Griffin RJ. Bystander Effects in Spatially Fractionated Radiation Therapy: From Molecule To Organism To Clinical Implications. Semin Radiat Oncol 2024; 34:284-291. [PMID: 38880537 PMCID: PMC11185274 DOI: 10.1016/j.semradonc.2024.05.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/18/2024]
Abstract
The standard of care for radiation therapy is numerous, low-dose fractions that are distributed homogeneously throughout the tumor. An alternative strategy under scrutiny is to apply spatially fractionated radiotherapy (high and low doses throughout the tumor) in one or several fractions, either alone or followed by conventional radiation fractionation . Spatial fractionation allows for significant sparing of normal tissue, and the regions of tumor or normal tissue that received sublethal doses can give rise to beneficial bystander effects in both cases. Bystander effects are broadly defined as biological responses that are significantly greater than would be anticipated based on the radiation dose received. Typically these effects are initiated by diffusion of reactive oxygen species and secretion of various cytokines. As demonstrated in the literature, spatial fractionation related bystander effects can occur locally from cell to cell and in what are known as "cohort effects," which tend to take the form of restructuring of the vasculature, enhanced immune infiltration, and development of immunological memory. Other bystander effects can take place at distant sites in what are known as "abscopal effects." While these events are rare, they are mediated by the immune system and can result in the eradication of secondary and metastatic disease. Currently, due to the complexity and variability of these bystander effects, they are not thoroughly understood, but as knowledge improves they may present significant opportunities for improved clinical outcomes.
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Affiliation(s)
- Samir V Jenkins
- Department of Radiation Oncology, University of Arkansas for Medical Sciences, Little Rock, AR..
| | | | - Ruud P M Dings
- Department of Radiation Oncology, University of Arkansas for Medical Sciences, Little Rock, AR
| | - Robert J Griffin
- Department of Radiation Oncology, University of Arkansas for Medical Sciences, Little Rock, AR
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